Multi-Monitor-Issues (XFCE)

English Hardware
1

I have a three monitor setup (2× 1920x1200 displays for normal work, and besides it, my 55″ TV with 1920x1080, connected via HDMI and an AV receiver.

All works as expected, but when I switch the inputs on the AV receiver (which means if the computer output is connected to the TV), the graphics on the desktop switches around.

Setting the “Connecting Displays: configure new displays when connected” to OFF in the XFCE display settings applet does nothing (still switches to the screen when I change the AV receiver input).

dmesg shows nothing when changes appear.

With one of the latest updates (see my other thread about HDMI sound issues), pulseaudio doesn’t survive such a display change, I have to kill pulseaudio and start it again in order to have sound again.

What I would need is to hardwire the 3rd display to 1920x1080 output, regardless whether something is connected or not. Perhaps it’s not part of the XFCE display settings, but deeper in the X11 settings, though. Any ideas how to do this?

2

In xfce4-settings-manager under display in advance tab you can save the profile of each of your monitor setup.

3

In Plasma, KScreen2 can be disabled so that it doesn’t try to apply automagic and move things around. If the positions and resolutions aren’t automatically to your satisfaction by disabling whatever XFCE uses for the same purpose, you can use arandr to create a script that can be applied on session startup, and reapplied any time unwanted shuffling occurs. Such a script might resemble the following (made with a plain text editor, not arandr):

xrandr --output DP-1 --primary --mode 1920x1200 --rate 60 \
--output DP-2 --mode 1920x1200 --rate 60 --right-of DP-1 \
--output HDMI-1 --mode 1920x1080 --rate 120 --right-of DP-2

Alternatively, /etc/X11/xorg.con* can be used to configure, but it’s more complicated to do than using xrandr, and can only be reapplied to Xorg, should it be necessary, by restarting it.

4

you twice write arandr, but the script mentions xrandr (which I’m familiar with). Just a typo, or another program I’m not aware of?

Thank you for the suggestion. Now I’ll only have to find out which component does the automatic switching. Not sure if this is deep in the system, because it might already show this behavior on the xdm login prompt (but I’m not 100% sure about it).

5

xrandr is the Xorg-sourced command line tool. arandr is a generic GUI tool that will generate an xrandr script that will configure your screen/display layout/positions as you wish.